Feb. 3, 2011 is a date that will live in infamy -- for some of us, anyway. That day marked the last time IANA will allocate a fresh /8 netblock to one of the Regional Internet Registries (ARIN, RIPE, and so on).
One could legitimately say that the Internet is indeed out of IPv4 addresses right now, but the pain won't really be felt until the RIRs deplete their allocations and ISPs burn through what they've already been allocated. That date will vary depending upon what part of the world you live in. The Asia-Pacific region is slated to run out first, but everyone else is close behind. Getting a good old dotted-quad IPv4 allocation from your ISP is going to be a fun bedtime story you can tell your kids within the next year or two.
[ Behind the curve on IPv6? Matt Prigge shows you how to build your own IPv6 lab on the cheap with everyday materials. Check out both parts, and you'll be right on top of the new protocol. | InfoWorld's Peter Bruzzese suggests that users get their Windows networks IPv6-ready while they still can. | Keep up on the latest networking news with our Technology: Networking newsletter. ]
Of course, as most technologies become overwhelmed by their own success, there's usually a replacement around the corner that's ready to jump in and save the day. In this case, that replacement is the much seen but rarely understood IPv6, and it's been around since 1998. Talk about a slow walk into the spotlight.
The IPv6 checklist
If you want to get started with IPv6, you'll first need an operating system that supports the protocol. Fortunately, you have one. I can almost categorically say so because every Microsoft OS since Windows 2000, Linux kernel since 2.1.8 (1998), and Apple OS X since 10.3 (2005) has had at least some form of support for IPv6. Newer operating systems even have it enabled by default, so it's probably turned on. Oddly enough, if you're reading this on a smartphone with 4G service, there's a pretty good chance you're using IPv6 right now.
Next you'll need an Internet connection that supports delivery of IPv6. This part is a bit trickier. Most subscriber Internet connections don't yet support native IPv6, but that is starting to change (welcome to IPv6, Littleton Colorado!). Many tier 1 and tier 2 ISPs that might be delivering bandwidth to your corporate network will also deliver IPv6 if you ask for it, but chances are you haven't yet. That's OK -- for our purposes, there's an easier way that won't require calling your ISP, replacing your cable modem (or your whole cable company), upgrading your firewall firmware, or hacking around in the configuration of your core router.
That easy way is through the use of an IPv6 tunnel. There are a multitude of different transitional technologies that exist to allow backward and, in a sense, forward compatibility between IPv6 and IPv4. To be precise, there is no real forward compatibility from IPv4 to IPv6 -- a device attached to an IPv4 network that is only running an IPv4 networking stack cannot interact with an IPv6 network at all (though there are tunneling technologies that will allow IPv4 networks to reach each other through an IPv6 network).
However, since almost every device you're likely to come across does have an IPv6 networking stack, you can run both IPv4 and IPv6 at the same time; this is usually referred to as a hybridized or dual-stack configuration. If the network you're attached to isn't already configured to handle IPv6 traffic (including routers, firewalls, and so on), you'll need to build an IPv6 tunnel from your machine through the IPv4 Internet to somewhere else that can act as a gateway onto the IPv6 Internet.